In a letter to their newborn daughter, Facebook founder and CEO Mark Zuckerberg and his wife Priscilla Chan pledged to donate 99 percent of their Facebook shares to charity so that their child may “grow up in a world better than ours today.”

Zuckerberg made his stunning announcement in a letter to daughter Maxima Chan Zuckerberg—aka Max—posted on Facebook on Tuesday.

“Your mother and I don’t yet have the words to describe the hope you give us for the future,” the letter begins. “Your new life is full of promise, and we hope you will be happy and healthy so you can explore it fully. You’ve already given us a reason to reflect on the world we hope you live in,” said Max’s parents. “Like all parents, we want you to grow up in a world better than ours today.”

“We will do our part to make this happen, not only because we love you, but also because we have a moral responsibility to all children in the next generation,” wrote Chan and Zuckerberg. “We believe all lives have equal value, and that includes the many more people who will live in future generations than live today. Our society has an obligation to invest now to improve the lives of all those coming into this world, not just those already here. But right now, we don’t always collectively direct our resources at the biggest opportunities and problems your generation will face.”

To that end, the couple, announcing the launch of their Chan Zuckerberg Initiative, pledged to “give 99% of our Facebook shares—currently about $45 billion—during our lives” to help solve some of the most pressing challenges facing humanity today.

“Our initial areas of focus will be personalized learning, curing disease, connecting people and building strong communities,” the couple wrote.

Their plan includes:

Improving health by combating disease: “Today we spend about 50 times more as a society treating people who are sick than we invest in research so you won’t get sick in the first place,” the letter states, promising to make “faster progress” fighting and curing heart disease, cancer, stroke, neurodegenerative and infectious diseases—the five deadliest diseases today.

Advancing human potential: Zuckerberg and Chan ask if we can “connect the world so you have access to every idea, person and opportunity, harness more clean energy so you can invent things we can’t conceive of today while protecting the environment [and cultivating] entrepreneurship so you can build any business and solve any challenge to grow peace and prosperity?”

Promoting equality: The couple stress the paramount importance of “making sure everyone has access to these opportunities—regardless of the nation, families or circumstances they are born into,” asking if our generation can “eliminate poverty and hunger, provide everyone with basic healthcare, build inclusive and welcoming communities, nurture peaceful and understanding relationships between people of all nations [and] truly empower everyone— women, children, underrepresented minorities, immigrants and the unconnected?”

“If our generation makes the right investments, the answer to each of these questions can be yes—and hopefully within your lifetime,” Chan and Zuckerberg assert, adding that advancing human potential and promoting equality “will require a new approach for all working towards these goals.”

“Once we understand the world we can create for your generation, we have a responsibility as a society to focus our investments on the future to make this reality,” the parents write, adding that “together we can succeed and create a more equal world.”

But the new parents also recognize formidable obstacles standing in the way of their goals.

“If you have an unhealthy childhood, it’s difficult to reach your full potential,” they write. “If you have to wonder whether you’ll have food or rent, or worry about abuse or crime, then it’s difficult to reach your full potential. If you fear you’ll go to prison rather than college because of the color of your skin, or that your family will be deported because of your legal status, or that you may be a victim of violence because of your religion, sexual orientation or gender identity, then it’s difficult to reach your full potential. We need institutions that understand these issues are all connected.”

The Chan Zuckerberg Initiative is just one of the Facebook founder’s philanthropic endeavors, albeit by far the largest. On Monday, Zuckerberg announced he will partner with Microsoft co-founder Bill Gates, Amazon founder and CEO Jeff Bezos, British business mogul Richard Branson and other tech and business leaders to launch the Breakthrough Energy Coalition, which will invest in zero-carbon energy technology in various nations.

The New York Timesreports Zuckerberg and Chan, who is a physician, have recently made major investments in kindergarten-through-high school education projects.

AltSchool, a San Francisco-based private school startup that develops personalized learning technologies, announced in May that it had raised $100 million from investors including a donor-advised fund financed by the Zuckerbergs at the Silicon Valley Community Foundation. In September, Facebook announced it was working with Summit Public Schools, a network of charter schools, to develop online tools that will improve how individual students are taught. Chan and Zuckerberg also recently agreed to donate $20 million to EducationSuperhighway, a nonprofit helping schools obtain federal funding for high-speed Internet in classrooms.

The couple will undoubtedly learn from—and improve upon—their much-maligned 2010 donation of $100 million to public schools in Newark, New Jersey. Ken Berger, CEO of Charity Navigator, told CNBC that while Zuckerberg’s intentions were laudable, his massive donation was not very carefully thought-out.

“We see this very often, that people start from the heart… but then when it comes to the question of using the community, engaging the community, sometimes that gets lost and there’s a top-down approach that occurs where there’s a disconnect with the realities on the ground,” Berger said. “Here we had a foundation with only millionaires on it.”

According to the New Yorker, between 2010 and 2012, more than $20 million of Zuckerberg’s gift, and subsequent matching donations, was spent on “consulting firms with various specialties: public relations, human resources, communications, data analysis [and] teacher evaluation.”

“Everybody’s getting paid, but Raheem still can’t read,” Vivian Cox Fraser, president of the Urban League of Essex County in New Jersey, told the magazine.